Re' Marketplace Silence Theme

Can anyone help please, because I'm not getting a lot of help from the theme developer and the theme worked perfectly until I did the theme update?

My websitehttp://www.getthebigidea.co.uk which is supposed to work responsively, doesn't work responsively. The key to making this work is by setting the auto-nav custom template to "Silence Nav" which I have done and it still doesn't work responsively.

Also the sitewide nav setting doesn't work now, because the nav appears to have different setting on different pages. For instance, if you go tohttp://www.getthebigidea.co.uk/portfolio/... the setting appears to be a "mobile only" nav menu, but when I look at the custom template for the nav, it is set correctly for the responsive setting "Silence Nav" as are all the others.

Also when I leave this page (http://www.getthebigidea.co.uk/portfolio/) while in edit mode, the website signs itself out of edit mode. It also does this if I go from any page (eg the homepage) to this particular page in edit mode. In fact the only it will allow me to visit this page and stay in edit mode is if I go in via the sitemap.

The whole things seems of got screwed some-how! I'd be grateful for any help from my fellow C5'ers please, as I'm pulling my hair out now.

Thanks guys
David